A:CH3COOH
B:HOOC—COOH
C:HOCH2CH2OH
D:HOCH2COOH
下列纬线中最长的是( )
Food is very important to our health. Everyone needs to eat well if he or she wants to have a strong body.Our minds, like our bodies, always need the best food. This kind of food is knowledge. We start getting knowledge when we are very young.
关于力与运动的关系,下列说法正确的是()